Mechanism for counterbalancing pivotally-mounted bodies



E K. STANDISH. MECHANISM FOR COUNTERBALANCING PIVOTALLY MOUNTED BODIES.

APPLICATION FliED MAY22.1920.

PatentedSept. 5, 1922.

2 SHEETS-SHEET 2.

E. K. STANDISH.

APPLICATION FILED MAY 22. I920.

' Patented Sept. 5, 1922.

2 SHEETS-SHEET MECHANISM FOR COU-NTERBALANCING PIVOTALLY MOUNTED Bum.

i atented Sept, 5, 19.22.

EDWARD K. STANDISI-I, OE STOUGHTO'N, MASSACHUSETTS.

MECHANISM FOR GOUNTERBALANGING PIVOTALLY-MOUNTED BODIES.

Application filed May 22, 1920.

Serial No. 383,588.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L., 625.)

To all whom it may concern:

Be it known that I, EDWARD K. STANDISH, a citizen of the United States,and a resident of Stoughton, county of Norfolk, State of Massachusetts,have invented an Improvement in Mechanism for Counter-balancingPivotally-Mounted "Bodies, of which the following is a specification.

The invention described herein may be used by the Government, or any ofits otlicers or employees in prosecution of work for the Government, orby any other person in the United States, without payment to me of anyroyalty thereon, in accordance with the act of March 3, 1883.

The subject of this invention is an equilibrator designed for thepurpose of counterbalancing pivotally mounted bodies and more especiallyto counter-balance a gun barrel.

In ordnance practice, the barrel of the cannon or like gun is mounted ontrunnions so as to oscillate about an axis passing through orsubstantially through the center of gravity of the barrel.

As the oscillatory movement of the gun body or barrel is for the purposeof permitting elevation or depression in directing lire, it is evidentthat the axis about which such movement takes place must pass throughornear the center of gravity of the barrel in order that the barrel may becapable of being rocked upon its trunnions without undue effort.

With the appearance of aircraft in warfare, it became necessary todevise some means of combatting them, and vtor this purpose ananti-aircraft gun was designed. As such a gun, to be eflective. requiredan angular range of elevation of ninety degrees or thereabout, it isevident that mounting the gun barrel in the usual .way, with the weightof the barrel so distributed on either side of the axis of oscillationas to counterbalance cannot be resorted' to unless the gun is supportedon an exceedingly high mount, because that portion of the barrel totherear of the axis will be of such a length that, when the gun is nearmaximum elevation, the breech will strike the ground on recoil.

This difficulty is overcome by having the axis about which the gunoscillates located nt l y at he breech. Such elevation of the gun givesrise to another difficulty, especially in large guns of this character,which is that the weight of the barrel is so great as to make itimpossible to elevate the same by the ordinary and practical mechanismdevised for this purpose.

To overcome this difliculty means .for counter-balancing the gun barrelhavevbeen devised, such means usually consisting of a crank armextending downward from the gun. barrel and-urged forwardly by aresilient element producing a turning moment about the axis of thetrunnions contrary to the .moment produced by the weight of theforwardly projecting gun barrel;

This means of counter-balancing the gun barrel contains two inherentdefects; viz: an undue thrust against the trunnion bearings and a forcewhich does not proximate and counter-balance the weight of thevbarrelfor all positions of elevation thereof.

It is found that the turning moments produced by the weight of thebarrel in its various positions of'el'evation vary, and that suchvariation is irregular giving a diagram of moment, in the form of areverse curve. From this it will be apparent that a series ofcounter-balancing forces must be brought into play, which forces may beapplied successively to counter-balance the successive turning momentsdue to weight and position of the barrel. 1

The equilibrator which is the subject of this invention was devised toovercome the foregoing difiiculties. I

It is also within the contemplation of'the invention to generallyimprove the construction and enhance the utility of equilibrators. It isalso desired to eliminate the friction of packing inherent in mostdesigns and which becomes very serious with the extremely highpressuresand weights necessary. I y

It is also desired to secure a construction which will allow of positivesealing of the fluid under pressure and which will allow of a variationin the initial and fin'alpressures of expansion at various points in thecurve of travel. v

It is also desired to secure a construction which will combine lightnesswith strength and which will give great length of action 5 and in itselfoccupy only a small space.

departing from the spirit of the invention- A practical structure forcarrying out the invention is illustrated in the accompanying drawings,wherein Figure 1 is a fragmentary view in side elevation of anantiaircraft gun. equipped with an equilibrator constructed inaccordance with the invention.

Figure 2 is a longitudinal section of the equilibrator, parts brokenaway.

Referring to the drawings by numerals of reference An anti-aircraft gunis indicated, generally, at 1 which is provided with trunnions 2 so asto be supported for oscillation on the gun mount 3.

The equilibrator 4; may be connected to the gun in any suitable way,but, as herein shown, it is provided with trunnions 5 which arejournaled in bracket arms one of which is shown at 6, extending from thegun mount 8.

The equilibrator 4t consists of a series of elements adapted tosuccessively exert pres sure upon the gun barrel 1, but, as hereinshown, 7 it is composed of telescoping or nested cylinders 7 eachprovided at its inner end with an outwardly extending annular flange 8,formed with apertures 9 spaced about its periphery. The innermostcylinders are formed with inset rear ends or hottoms 10 and 11,respectively, the distance at which such bottoms are inset beingcontrolled by the air space required. The cylinder next to the outercylinder is preterably provided with a flat inner end or head 12 whichis integral with the flange 8 of such cylinder, and the rear or lowerend of the outermost cylinder is closed by head 13.

Fitted within the inner cylinder, to slide longitudinally thereof, isa'piston 1% formed with apertures 15 spaced about its periphery andhaving a piston rod le'extending torwardly therefrom and through thehead 18 of the cylinder and terminating in an apertured head or eye 17by which the equilibrator may be suitably articulated to the gun barrel.1

Each cylinder is closed at its outer or upper end by a cap 18 which ispreferably, as herein shown, threaded on the cylinder. A passage 18 isformed in each head or cap 18 which is adapted to be closed by a valve19, the purpose of the passage and valve being to permlt air underpressure to be forced into thecylinders. I The device isdesigned tooperate under compressed air for the reason that adiabatic (EXPElIlSlOnor compression gives a curve more nearly approximating that portion ofthe curve of the diagram of moments to through the ports 18 is outsideof the hellows and free to pass through the apertures 9 and'15, but isprevented by the bellows from coming in contact with the sliding jointsbetween the piston rod 16 or the cylinders '7 and the cylinder heads 18.

An air escape port 21 may be supplied when desired in the heads 18 ofthe cylinders for the purpose of permitting air within the bellows toescape after the bellows are contracted and so prevent compression ofthe air within the bellows and consequent loss of effective pressure inthe device.

In practice, when the gun is elevated, the piston 12 rises in theouter-most cylinder '7 under the force of the compressed air containedwithin such cylinder and tends to counter-balance the weight of the gunharrel during the early states of its elevation. l l hen the piston 12has advanced sufiiriently to bring; the shoulder 23. formed on itscylinder 7, into contact with the head 18 of the outermost cylinder,travel of the piston with relation to such outermost cylinder will Themaximum countcr balancing pressure is required when the gun horizontal,and the higher the elevation the less the pres sure required forcounterbalancing the gun. The piston head 12 presents the greatest areaand the pressure against this head will be sufiicient to exactly-ounter-balancc the gun at 0 elevation. and by properly proportioningthe volume oi air at the initial and final positions of piston 12 thegun can be balanced throughout this part of its elevation. It will thusbe seen that by securing the correct initial pressure against pistonhead 11 to exactly balance the final upward pressure against the pistonhead 12 at the time the shoulder 23 contacted with the head 18, piston11 will continue to balance the gun on further elevation until shoulder24 hits flange 8 of piston head 11. V

By having the resulting initial upward pressure on the piston 10 equalto the final upward pressure on piston 11, piston 10 will balancetlie'gun through its movement upward until shoulder 25 hits the head 18By having the resulting initial upward pressure on piston head 1%equalto the final ]pressure on piston head 10, piston 14 will alance theupward movement of the gun through the last part of its elevation anduntil the shoulder 22 hits head 18.

It will be noted that by this construction the pressures in each of thefour separate cylinders will be approximately the same as the areasexposed, decreasing about in proportion to that required to maintainbalance.

By this construction of four separate sealed telescoping cylinders, itis possible to design the volumes, both initial and final so thatpressure will follow closely the curve of pressures required to balancethe gun.

in this manner the air pressure in each cylinder is brought intosuccessive operation until the shoulder 22 of the last or innertelescoping cylinder engages the cap or head 18 of the innermostcylinder which is the.

limit of movement of the device.

In lowering the gun barrel, a reverse ac tion of the cylinders andpiston takes place.

Having described my invention, What I claim as new and desire to secureby Letters Patent, is V 1. The combination of an oscillatable gun andmeans for aiding oscillatory movement thereof comprising an outercompressed air cylinder, telescoping compressed air cylinders nestedwithin said outer cylinder and movable relative to each other and tosaid outer cylinder, the inner end walls of said nested cylinders beingprovided with annular extensions projecting therebeyond, and bellows insaid cylinders disposed between the said extensions and the outer endwalls of said cylinders. I

2. The combination of an oscillata-ble gun and means for aidingoscillatory movement thereof comprising an outer compressed aircylinder. telescoping compressed air cylinders'nested withi said outercylinder and movable relative to each other and to said outer cylinder,and annular flanges on the inner ends of the cylinders, said flangesprovided with apertures to permit the passage of 'essure fluidtherethrough.

3. The combination of an oscillatory gun and means for aidingoscillatory movement thereof, comprising a plurality of teleseop .4,bellows associated with each cylinder.

4. The combination ofan oscillatable gun, and means for aidingoscillatory movement thereof, including a plurality of telescopingcylinders and flexible bellows associated with the cylinders.

5. The combination of an oscillatable gun and pneumatically-controlledmeans for aiding oscillatory movement thereof said means includingflexible bellows.

6. The combination of an oscillatable gun and fluid-controlled means foraiding oscillatory movement thereof said means includin flexiblebellows.

4. The combination of an oscillatalole gun and means for aidingoscillatory movement thereof said means including flexible bellows.

8. The combination of a movable. body of means for applying successivelychanged pressures to said body said means including flexible bellows.

9. The combination of a movable body presenting during movement,successively changed resistances to motion and means for applyingsuccessively changed pressures to said body to counteract suchreslstances said means including flexible bellows.

10. An equilibrator, including nested cylinders, flexible bellowsassociated with said cylinders and means for moving, successively, thecylinders with relation to each other.

11. An equilibrator, including an outer cylinder, telescoping cylinderswithin the outer cylinder, flexible bellows connected to the telescopingcylinders and means for moving, successively, the telescoping cylinderswith respect to each other and to the outer cylinder. 1,

12. An equilibrator for cannon, including nested cylinders movable withrelation to each other, means for admitting pressure and flexiblebellows fluid to the cylinders,

fluid in the for retaining the pressure cylinders.

18. An equilibrator for cannon comprising means for storing pressurefluid including flexible bellows.

let. An equilibrator for cannon, including nested flexible bellowsmovable with respect to each other.

EDWARD K. STANDISH.

compressed-air cylinders and a flexible

